Conventional membrane-based processes, such as ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO) require hydraulic pressure to drive the system. This can require significant energy consumption. An integrated forward osmosis-membrane distillation (FO-MD) system has been proposed where the membrane distillation (MD) feed and forward osmosis draw solution (FO DS) flow in the same channel simultaneously (same feed in contact with the MD and FO membranes at the same time). This, however, causes mixing of forward osmosis (FO) permeate with membrane distillation (MD) feed, and dilution and cooling of the MD feed by the FO permeate, which can lower efficiencies.